________ sphericity and ________ macro or micro-surface roughness promote sintering.

________ sphericity and ________ macro or micro-surface roughness prom

1.	________ sphericity and ________ macro or micro-surface roughness promote sintering.
A.	Decreasing, decreasing
B.	Increasing, decreasing
C.	Decreasing, increasing
D.	Increasing, increasing
Answer» D. Increasing, increasing